Soilless cultivation of vegetables in greenhouse

The maturity is as follows: 1. Main technical methods 1. Fermentation of straw cultivation substrate. Preparation before straw composting: (1) Crop straws such as wheat straw and corn straw can be selected, and the amount of straw should be twice the volume of the culture tank. For example, when planting cherry tomatoes in a standard greenhouse (666.7 square meters), the volume of the cultivation pot is about 20 cubic meters, and the volume of the wheat straw is more than 40 cubic meters. First, cut the straw into pieces, the length is not more than 4 cm, and then soak it in water for later use. (2) Straw composite microbial preparation is used for straw composting and fermentation. (3) One week before straw composting, 4 cubic meters of cow dung is mixed with straw decomposing bacteria, so that the straw decomposing bacteria can propagate in the cow dung. (4) The dosage of urea is about 0.5% of the amount of straw, and 40 cubic meters of straw needs 25 kilograms of urea. Straw pile rot method: the bottom of straw pile is 2m wide and1.8 ~ 2.0m high, and the length is not limited. Every 20 cm of straw, sprinkle a layer of cow dung mixed with straw decomposing bacteria and appropriate amount of urea. If the straw is not saturated with enough water, spray a proper amount of water and hold the straw tightly with your hands, and the water will be squeezed out between your fingers. This method is to pile the straw to the height of 1.8 ~ 2.0 meters, and the pile is completed. Then covered with plastic film to reduce the evaporation of water in the pile. After 2 ~ 3 days, the temperature in the reactor can reach above 70℃; /kloc-turn over the pile in about 0/5 days, and turn the straw at the edge into the middle of the pile to further mix the straw and cow dung evenly. If the straw is dry, a proper amount of water can be added; It will rot after turning over the pile 15 days. Straw is semi-decomposed, inflexible and broken by hand, and the C/N ratio is between 30 and 40, which can be used as the substrate for soilless culture. 2. Cultivation techniques. (1) culture pond: the culture pond adopts the method of digging ditches and laying plastic film. Take the cherry tomatoes as an example: the cherry tomatoes are planted in different rows, the row spacing is 60 cm ~ 70 cm, and the cultivation grooves are dug in a single row. The cultivation tank is triangular in shape, with an opening at the top of 20 cm and a depth of 25 cm, and the bottom of the tank should be flat to avoid local water accumulation; Paving a plastic film of 0.65438 0 mm in the culture pond; Filling plastic film with fermented straw as matrix, and stepping firmly with feet; Plant cherry tomato seedlings with a spacing of 35 cm. (2) Installation of drip irrigation equipment: Drip irrigation equipment is very important for soilless culture, and it is a necessary equipment for supplying inorganic nutrients and water. The main drip irrigation equipment includes power equipment, fertilizer box, filter, water meter, branch pipe and capillary. Power equipment includes water tower, variable frequency submersible pump with centralized water supply, etc. In the Yellow River Plain where the groundwater level is shallow, a plastic hose well can be drilled in the greenhouse, driven by a self-priming pump to meet the pressure of drip irrigation in the greenhouse. The fertilizer box is specially designed to reduce the water pressure loss and solve the problem of fertilizer blocking the filter, and has been authorized by the national utility model patent; The branch pipe can be made of polyethylene pipe with a diameter of 32 ~ 40mm; The distance between drippers in the capillary is 20 cm, and the distance between drippers is close, which is beneficial to the absorption of vegetable roots. When laying the drip irrigation pipeline, the branch pipe should be parallel to the back wall of the greenhouse, preferably disconnected in the middle, and connected with the fertilizer box with a tee, so that the water flow can be diverted from the middle to both ends, and the pressure of the whole drip irrigation is relatively uniform; Laying a capillary in each row, so that the capillary is in the middle of the cultivation tank as far as possible, and the emitter face is upward, which can reduce the blockage of drip irrigation. (3) Nutrient solution management: A nutrient solution management method suitable for cultivation system was researched and invented. By adding nutrient solution and fertilizer to the substrate, the traditional concept and management method of nutrient solution were changed. Traditionally, nutrient solution is prepared by dissolving a large number of medium and trace element fertilizers together. Because the groundwater in the north is generally alkaline, chemical precipitation is easy to occur in the preparation process, and it is difficult for farmers to control the pH value of nutrient solution with acid. There is also a method of complexing heavy metal ions to solve chemical precipitation, which has high cost; The problem of nutrient solution has become a bottleneck in the popularization of soilless culture technology; In addition, the investment of nutrient solution preparation pool is also high. In this technology, nutrient solution fertilizers are directly added to the matrix in groups, and fertilizers that can form chemical precipitation are separated. Firstly, adding a group of fertilizers into a fertilizer tank, dissolving the fertilizers during drip irrigation, and then dripping into a substrate, when the fertilizers are completely dissolved; Stop drip irrigation and add another set of fertilizer until the drip irrigation is over. Management method of nutrient solution: at the initial stage of planting, the root system of vegetables is very small, and the nutrient solution of most emitters can not be absorbed by the root system, resulting in waste. A certain amount of nitrogen, phosphorus and potassium fertilizer can be dissolved in a barrel, and the concentration is about 1g/L, and it can be artificially poured around the seedlings once a day for about 10 day. After the roots are basically connected, drip irrigation is normally used to supply nutrient solution; At the initial stage of supplying nutrient solution by drip irrigation, due to the small seedlings and small amount of water and fertilizer, 0.5 cubic meters of water and fertilizer were dripped every day, once in the morning and once in the afternoon, and a group of fertilizer was added each time; In autumn and winter, according to the seedling situation and weather conditions, the daily irrigation amount is generally controlled at about 1 m3, drip irrigation is carried out in sunny morning, and no irrigation is carried out on cloudy day; The irrigation amount can be determined by observing the accumulation of nutrient solution in the culture tank. In spring, the temperature is high, the sunshine is sufficient, and the growth of cherry tomatoes is large. The daily water and fertilizer consumption of drip irrigation is 1.5 ~ 2 cubic meters. 3. Cultivation effect. The sugar content of cherry tomato cultivated by this technology is 26.3% higher than that cultivated by soil. Pure taste, sweet and sour taste, fragrant aftertaste, better taste than local cultivation; Reduce the amount of pesticides, which are planted in soil1/4; Save water and fertilizer, with water consumption per shed150m3 and fertilizer consumption per shed 1500 yuan, which reduces fertilizer input by about 350 yuan/shed compared with soil planting; The output is basically flat, and the overall benefit has increased by more than 20%. two